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OK, so how about: no double checking to try to resolve the conjecture nearly twice as quickly, but if and when it gets down to only one k with unknown status, run a double check on those.

----Added----

I'll make an analogy. Suppose that there are a large number of boxes. A small number of boxes contain a diamond and you want to find diamonds. The first time you look in a specific box, if it contains a diamond, there is a 5% chance that you will not see it.

Should you (1) spend half of your time double-checking boxes you have already opened, or (2) open as many boxes as you can? I would open as many boxes as I can.

It is important to note that the boxes are numbered, and
1) The lower numbered boxes are more likely to contain a diamond than the higher numbered boxes.
2) The higher numbered boxes are harder to open than the lower numbered boxes.

It is important to note that the boxes are numbered, and
1) The lower numbered boxes are more likely to contain a diamond than the higher numbered boxes.
2) The higher numbered boxes are harder to open than the lower numbered boxes.

Taking that a bit further, the difficulty of opening the boxes is proportional to the square of the box number, and the overall chance of finding a diamond (taking into account how hard it is to open the box as well as the likelihood of a given box containing a diamond) is inversely proportional approximately to the cube of the box number times the logarithm of the box number. Diamonds in higher numbered boxes are much harder to find. You really don't want to miss the easy ones, ever.

The allure of progressing twice as fast is obvious, but the penalty for missing a prime is tremendous.

I like to remind you guys that at least one of the primes was found via secondpass - that means a prime was missed with the firstpass tests, aka we already had a false negative - right in the SoB project. (the one at ~3M)

All true. Just saying. Hate to go 10 miles down the road and find out we missed the turn.

Originally Posted by chris

Greetings,

about the double check discussion.

I like to remind you guys that at least one of the primes was found via secondpass - that means a prime was missed with the firstpass tests, aka we already had a false negative - right in the SoB project. (the one at ~3M)

I also believe double checks are worth it. Basically, if we have a 5% error rate, then it's even faster to find a prime if we can complete a double check in 1/20th the time of an initial check.

A recent change at GIMPS is to send out a double check assignment to everyone when they first join and once every year. This helps the project find bad computers quickly so their work can be double checked immediately. Sending out a double check at the beginning is also good in that new users get to finish something sooner.

Rest assured that someone (probably me, unless Louie jumps in) will let you know any information as soon as we know anything.

I did say I'd let you know as soon as I heard anything, so here it is. It's not good news, unfortunately.

There's no hope of recovering the data or software from the SoB server. It's gone. SoB is not coming back.

Louie has asked us to take over the entire SoB search. We intend to do so, but I can't tell you exactly what that means. For now, we are crunching all 6 Ks in the 31M < n < 32M range, and we'll continue with that until we decide how to move forward.

You are all, of course, welcome to come on over to PrimeGrid and help with SoB.

I'd like, at this point, to sincerely thank everyone who sent us their log files. Of all the information we've been able to gather from different sources, I suspect that your log files may end up being the most useful. They contain the most recent information, regarding the largest tasks. Those are most useful.